1. Field of the Invention
The present invention relates to a method for forming a light-emitting case and a related light-emitting module, and more specifically, to a method for utilizing an IMD (In-Mold Decoration) process to sheathe a PLED device with a case and a related light-emitting module.
2. Description of the Prior Art
In general, a light-emitting case is usually used for illuminated display of models, trademarks, or function key patterns on an electronic device, providing additional light in a dark environment, or generating a flashing warning.
In the following, illuminated display of function key patterns on a mobile phone is taken as an example. A common method involves disposing a spot light source (e.g. a white LED) or a surface light source (e.g. a cold light source) under a transparent control board where a pattern layer corresponding to the function key patterns is printed. When a user wants to use the function keys to perform corresponding operations (e.g. answering the phone, sending messages, dialing phone numbers, etc.), the said light source disposed under the transparent control board is switched on. Subsequently, light emitted by the light source passes through the pattern layer so that the function key patterns on the pattern layer may be illuminated accordingly. Thus, even in a dark environment, the user may still view the locations of the function keys clearly.
Please refer to FIG. 1, which is a diagram of a light-emitting module 10 according to the prior art. As shown in FIG. 1, the light-emitting module 10 utilizes a spot light source 12 for brightening a case 14. In order to generate uniform light distribution on the case 14, it is necessary to dispose a light guide mechanism on the light-emitting module 10. However, the additional light guide mechanism may not only complicate the structural design of the light-emitting module 10, but may also increase the manufacturing cost of the light-emitting module 10.
Furthermore, as shown in FIG. 1, if the case 14 has a curved surface, disposal of additional reflection pads 16 along with the curved surface is necessary for guiding light toward each portion of the case 14 uniformly. However, the said complicated disposal of the reflection pads 16 may ruin the appearance of the light-emitting module 10. Furthermore, brightness attenuation caused by multiple reflections of light may also result in uneven brightness distribution on the light-emitting module 10.
Thus, how to manufacture a light-emitting case capable of generating uniform light distribution without an additional light-guide mechanism that is suitable for a curved surface should be a concern in light-emitting module structural design.